Place one whole chicken or the bones of a roasted chicken into a slow cooker with bay leaves, black peppercorns, onion, carrots and celery. Cover with water and cook on low for 24 hours.

After 24 hours, pour broth through a fine-mesh sieve or a reusable coffee filter. This will help to clarify the broth.

Strain off any remaining broth and discard the bones. The bones from the chicken should crumble when pressed between your thumb and forefinger. This softness is an indication that the nutrients from the bones – minerals and amino acids – have leached from the bones into the broth.